JPS5871370A - Automatic controller for vapor deposition of metal on roll-film - Google Patents

Abstract

PURPOSE:To control vapor deposition of a metal automatically and stably with high accuracy by providing an automatic voltage regulating circuit for an electric power generator consisting of an output voltage setter and an output voltage detector as the 1st loop and an automatic film thickness regulating circuit consisting of a regulator for the rate of deposition of metals and a sensor for the thickness of vapor deposited films as the 2nd loop. CONSTITUTION:If V0 of a setter 8 for the rate of vapor deposition is increased in the case of increasing, for example, the rate of vapor deposition on a film 7, the output V2 of a detecting amplifier 9 increases as well. This voltage V2 is one of the inputs to a voltage amplifier 12, and the voltage V4 corresponding to a difference from the input voltage V3 from a voltage setter 13 is inputted to a main amplifier 14. Therefore the output of the amplifier 14 increases and controls the base of a transistor 17 connected to the magnetic field coil 16 of a high frequency power generator 1, thereby applying a change to the magnetic field current. Here, the output of the generator 1 is picked up with a detector 15 for high frequency output voltage, and the detected voltage V5 is compared with the previously inputted voltage V4. When the V4 and V5 attain equality, the increase in the magnetic field current ceases and the output of the generator 1 is made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION A high-frequency generator is generally used as a means for supplying high-frequency output to the induction furnace in a vacuum deposition apparatus that deposits melted metal vapor into a thin film in a vacuum in a high-frequency induction furnace. There is.

Conventionally, in this type of vacuum evaporation apparatus, as shown in FIG. 1, high-frequency power generated by a high-frequency generator 1 is supplied to a coil 4 of a high-frequency induction furnace 3 to heat and melt metal (not shown) placed in the furnace. and steam. On the other hand, induction furnace 3
A thin film 7 is sent out from the delivery roll 5 and wound onto the first winding roll B at the opening 2 which is a steam ejection hole.
is passing at a constant speed. At this time, the metal vapor heated and melted in the induction furnace 3 is deposited and fixed on the film 7 in a vacuum.

Conventionally, in order to make the amount of film 7 deposited uniform, this type of vacuum evaporation apparatus keeps the temperature of the induction furnace 3 constant and adjusts the feed rate when the film 7 passes over the surface of the opening 2 of the induction furnace 3. It is also necessary to make it uniform. Therefore, monitoring of temperature and feed rate is required. Therefore, when changing the thickness of the deposited film, it is necessary to finely adjust the temperature of the induction furnace and the feed speed of the film by manual operation, which reduces work efficiency and makes it difficult to maintain uniform quality. There wasn't.

The present invention eliminates such drawbacks of the conventional technology and automatically stabilizes the field current of the high-frequency generator that supplies heating power for the induction furnace 6 in response to changes in the amount of vapor deposited on the film and changes in the film feeding speed. Let it become.

The purpose is to automatically follow the temperature rise of the induction furnace to obtain a film of a predetermined thickness, as well as to improve efficiency and make the product uniform.

Next, one embodiment of the present invention will be explained with reference to FIG. is heated to a high temperature to vaporize it and deposit it on the film 7. The deposition amount is changed by means of a deposition amount setter 8, and the voltage thus set is input to one input terminal of the detection amplifier 9. In addition, the detection amplifier 9
The output of the film thickness measuring sensor 10 of the induction furnace 6 is inputted to the other input terminal via the time constant converter 11. The output of the detection amplifier 9 is the output voltage setter 13 of the high frequency generator.
is input to the setting amplifier 12 together with the setting voltage. The setting amplifier 12 connects the output V2 of the detection amplifier 9 and the output voltage setting device 1.
The difference v between the three set voltages V is output, and this output v4 is input to the main amplifier 14 for automatic voltage adjustment. On the other hand, the output voltage V of the high frequency output voltage detector 15 that detects the high frequency output voltage of the high frequency generator 1 is input to the main amplifier 14, and the output voltage V is input to the main amplifier 14.

The difference between and V is amplified and causes the field current to increase or decrease, thereby increasing or decreasing the generator output voltage +
It stabilizes when the difference between v4 and VB becomes almost zero. Further, the output of the main amplifier 14 is connected to the base of a semiconductor element 17 such as a transistor or a thyristor for controlling the current of the field wire ring 16 of the high frequency generator 1.

Next, the operation of the present invention described above will be explained in detail.

As shown in the voltage values of each input/output section, the output voltage of the high frequency generator 1 is first set by the voltage V of the output voltage setting device 13, and the temperature of the high frequency induction furnace 3 is maintained at a specified value. shall be taken as a thing.

An example of increasing the temperature in order to obtain a thick film with an increased amount of evaporated film 7 will now be described.

Now the voltage V of the film deposition amount setting device 8. One input of the total increaser 12 and the already set voltage setter 16
It is input to the setting amplifier 12 together with the input voltage v3 from . The voltage setting amplifier 12 outputs the difference between these two forces,
The output voltage becomes a voltage v4 corresponding to v2-v3. At this time, the output of the main amplifier 14 which receives the voltage V4i as one input increases, and the base of the transistor 17 connected to the field wire ring 16 of the high frequency generator 1 is controlled to change the field current. That is, the voltage V of the vapor deposition amount setting device 8. When the total is increased, the field current also increases, and this increase in field current increases the high frequency output voltage. Here, the output of the high-frequency generator 1 is picked up by a high-frequency output voltage detector 15 constituted by a high-frequency transformer, and the detected voltage V is added to the input of the main amplifier 14, and the previously input voltage v4
When the value of V becomes approximately equal to the value of v4, the field current stops increasing and the output voltage of the high frequency generator becomes approximately constant.

That is, when the setting of the vapor deposition amount setting device 8 is increased, the output voltage of the generator 1 increases, and the output current increases.

The temperature of the induction furnace 3 rises, and metal vapor increases.

The amount of vapor deposited on the film increases, and the thickness of the vapor deposited film increases.

This film thickness value is detected by a film thickness sensor 10.

After passing through the time constant converter 11, the voltage value v1 is output to the detection amplifier 9.
input. In this automatic control circuit, the film thickness value v1 corresponds to the set deposition amount V. Equilibrium is stabilized when it becomes approximately equal to .

The time constant converter 11 effectively acts to keep the deposited film thickness constant when the speed of the film 7 changes for some reason. The time constant converter 11 is a type of proportional-integral amplifier, and the output gradually changes over a certain period of time in response to a change in the input.

Taking as an example the case where the film speed increases, in this case, since the amount of vapor is constant, the amount of film evaporated decreases and the film thickness becomes thinner.

Therefore, the detected value of the film thickness sensor decreases by the amount of thinning and is input to the time constant converter 11, but its output v1 gradually decreases, and therefore the output v2 of the detection amplifier 91 also gradually increases. Gradually increase the generator output voltage and output current. When the generator output voltage and current are gradually increased, 9 generator voltage and induction furnace temperature, i.e. steam amount, vapor deposition amount.

Since there is no time lag between the film thickness and the film thickness, the film thickness will not exceed the set value due to overshoot.

If there is no time constant converter 11, the voltage of one generator will change rapidly, so the voltage of one generator, the temperature of the induction furnace, the amount of steam,
A time lag appears between the deposition amount and the film thickness, and the film thickness overshoots with respect to the set value.

As described above, the present invention has a generator automatic voltage adjustment circuit using an output voltage setting device and an output voltage detector as the first loop, and a metal deposition amount setting device and a deposition film thickness sensor as the second loop. The automatic film thickness adjustment circuit has an automatic film thickness adjustment circuit whose output corrects the output voltage setting of the automatic voltage adjustment circuit. A time constant conversion circuit (9) is provided to gradually increase/decrease the output of the automatic film thickness adjustment circuit, thereby preventing overshoot in film thickness adjustment. Therefore, it remains possible to perform stable and highly accurate automatic metal deposition control using this device.

Margin below

Claims (1)

[Scope of Claims] 1. Metal introduced into the induction furnace is melted and vapor deposited onto a roll film that moves close to the opening of the induction furnace by an induction furnace heated by a high-frequency generator and its output. In the vacuum evaporation apparatus, the first loop includes a main amplifier that compares and amplifies the detected value of the output detector of the high-frequency generator, the output voltage setting, and the set value of the device, and detects the evaporated film thickness of the roll film. with a film thickness sensor. a time constant converter that inputs the output thereof; a vapor deposition amount setter that sets the vapor deposition amount of the film; a detection amplifier that compares and amplifies the output of the time constant converter and the set value of the vapor deposition amount setter; A second loop constituted by a voltage setting amplifier that compares and amplifies the output of the amplifier and the setting value of the output voltage setting device, and the field coil current of the high frequency generator is controlled by the output of the main amplifier. An automatic control device for metal vapor deposition of a roll film, characterized in that the first loop and the second loop are completed by a field wire loop circuit.